The CBO score has made Trumpcare's biggest test even tougher

President Donald Trump Chip Somodevilla/Getty Images Despite the American Health Care Act drawing support from House Speaker Paul Ryan, Senate Majority Leader Mitch McConnell and President Donald Trump, the leadership's biggest problem still remains — senators in their own party.

"It's awful. It has to be a concern," said Sen. Bill Cassidy of Louisiana, who has introduced his own alternative to the AHCA. "President Trump said he wanted as many people covered as under Obamacare."

Republicans from stronghold states such as South Carolina, Louisiana, and Arkansas have expressed misgivings about the legislation after the CBO report, putting the future of the healthcare law in doubt.

'We need to do better'

Sen. Lindsay Graham of South Carolina said the CBO score should cause Republicans to delay their bill until they can make changes.

"At the end of the day we should pause and try to improve the product in the light of the CBO analysis rather than just rejecting it," said Graham, who has previously said the GOP should "slow down" on the healthcare overhaul.

And Sen. Tom Cotton of Arkansas launched into a lengthy rebuke of the AHCA on conservative radio host Hugh Hewitt's show. He said that while the CBO director "isn't Moses" when it comes to estimating the number of people losing coverage, he believed the CBO was "directionally correct" about the coverage losses.

Little margin for error

The biggest problem for Republican leaders is that only a few defections from the party are enough to derail the AHCA's path to Trump's desk.

The party holds a 52-seat majority in the Senate, so losing only three votes would prevent the law from passing. Given the number of senators that have previously said they have objections with the bill and the lawmakers that expressed doubts after the CBO score, there is a real chance that the GOP could have many more defectors.

Plus, Senate procedural rules could stop the bill in its tracks. The Byrd Rule does not allow a bill going through budget reconciliations — as in the case of the AHCA — to include anything that does not impact the budget's bottom line. Analysts and lawmakers have said that various aspects of the AHCA could violate the provision and stop the bill in its tracks.

The bill passed two House committees last week and will be considered by the House Budget Committee on Thursday.